Once the bands are on the birds, they ignore them, yet the bands tell us precisely whom we are observing. Bands are especially useful for tracking breeders that are evicted from their territories and young adults (that we band as chicks) that return to the study area to look for a breeding territory.

We employ a variety of techniques in our study, once our subjects are banded. Among the most important is routine observation of breeding pairs on the roughly 90 lakes in our study area. Hourlong visits to each lake allow us to confirm the identities of the breeders, record nesting behavior or presence of chicks and detect the visits of any intruders that happen to visit the lake when we are there. We also routinely record territorial yodels given by male breeders. view video clip here.

The recordings permit us to detect changes in the calls over time and to conduct simple, brief playback experiments that examine the responses of breeders and intruders to them. Another technique we have used to place decoys of adult loons and chicks in territories to see what effect they have on rates of intrusions into that territory by nonbreeders. All approaches we use to study loons must satisfy two requirements: 1) they must yield useful information about the behavior and/or ecology of loons, and 2) they must cause minimal disruption to the birds and have no impact on breeding success.